This invention relates to an artificial airway device designed to facilitate lung ventilation and the insertion of endotracheal tubes or related medical instruments into the laryngeal opening of an unconscious patient.
In general, laryngeal masks allowing for both rapid lung ventilation and the insertion of medical instruments and tubes into the laryngeal openings of patients have been described in patents such as Brain, U.S. Pat. No. 4,509,514. Consisting of two essential parts, a breathing tube and an inflatable mask, these instruments or devices are inserted blindly into a patient""s throat, and when properly positioned, terminate at the laryngeal opening. A seal is then formed around the circumference of the laryngeal opening by the inflation of a ring-like structure located on the front of the mask. Inflation of the ring exerts pressure against both the front and rear portions of the oropharynx, securing the device in place such that the laryngeal opening is positioned within a recessed cavity in the mask face. Extending from a point external to the oral cavity, the flexible breathing tube terminates within the recessed cavity, aligned axially with the laryngeal opening. The positioning of the flexible breathing tube allows the passage of small diameter endotracheal tubes or related medical instruments into the laryngeal opening, in addition to allowing for lung ventilation.
It has been discovered that laryngeal masks of the above-mentioned type have superior performance if its associated respiratory tube has an elliptical cross-section. This shape, however, can present a problem, since medical tubing (including the tubing for connecting to respiratory tubes) is typically circular in cross-section. This mismatch can create connection problems, leakage problems or even disconnections.
Among the several objects and advantages of the present invention include:
The provision of a new and improved laryngeal mask for the facilitation of lung ventilation and the insertion of endotracheal tubes and related medical instruments into the laryngeal opening;
The provision of the aforementioned laryngeal mask which includes an adapter for connection to medical instruments or devices, wherein the adapter includes at least one end that has an elliptical cross-section; and
The provision of the aforementioned laryngeal mask which includes an adapter for connection to medical instruments or devices, which includes raised ribs disposed circumferentially about the adapter for positioning of tubing.
Other objects will be in part apparent and in part pointed out hereinafter.
Briefly, a laryngeal mask of the present invention includes an inflatable positioning shield formed to fit within a patient""s oropharynx and seal around the circumference of the laryngeal opening. The shield has a recessed front to securely surround the trachea after inflation, preventing lateral movement of the laryngeal mask. The mask also includes a flexible respiratory tube having a proximal end, a distal end, a gently curved tubular body of sufficient size to permit passage of endotracheal tubes, and related medical instruments, and a lumen therethrough terminating within the recessed front of the inflatable positioning shield such that tubes and instruments passing through the flexible respiratory tube are directed into the laryngeal opening. The flexible respiratory tube has an elliptical cross-section, facilitating insertion of the laryngeal mask through the oral cavity. An adapter is coupled to the proximal end of the respiratory tube for connection of medical instruments or devices, the adapter including a body having a first end, a second end and a passage therethrough. The first end of the adapter has an elliptical cross-section for communication with the lumen of the flexible respiratory tube, and said second end has a cross-section which differs from the cross-section of the first end.
In a second aspect of the present invention, a laryngeal mask includes an inflatable positioning shield formed to fit within a patient""s oropharynx and seal around the circumference of the laryngeal opening, said shield having an inflatable annular toroid peripheral portion, a contoured rear portion, and a distal front portion. The mask also includes a flexible respiratory tube having proximal and distal ends, and a lumen therebetween defined by a gently curved tubular body. The distal end of the respiratory tube terminates within the front of the inflatable positioning shield such that tubes and instruments passing through the flexible respiratory tube are directed into the laryngeal opening. The flexible respiratory tube has an elliptical cross-section facilitating insertion of the laryngeal mask through the oral cavity. An adapter is coupled to the proximal end of said respiratory tube for connection of medical instruments or devices, said adapter comprising a body having a first end that has an elliptical cross-section, a second end that has a circular cross-section, a wall member disposed substantially centrally between said first end and said second end, and a passage therethrough.
In a third aspect of the present invention an adapter of the type suitable for connection of medical instruments or devices includes a body having a first end, a second end, and a passage therethrough. The first end has an elliptical cross-section for connection of tubing having an elliptical cross-section, and the second end has a cross-section that differs from the cross-section of the first end.
In a fourth aspect of the present invention, an adapter of the type suitable for connection of medical instruments or devices includes a body having a first end, a second end, a wall member disposed substantially centrally between said first end and said second end, and a passage therethrough. The first end has an elliptical cross-section for connection of tubing of a first kind and at least one raised rib disposed circumferentially around an external portion of said first end. The second end has a circular cross-section for attachment of tubing of a second kind.